In the fields of ultra-precision measurement and testing and ultra-precision machining, a clamping device with high speed, stability and precise positioning is the fundamental guarantee to precision measurement and aviation engine assembly. At present, with the progress in material science, as well as the increase in precision levels of ultra-precision measuring instruments and ultra-precision manufacturing equipment, designs of high-precision annular workpiece are applied more and more widely, and the devices used in the machining process becomes a basis for ensuring the machining precision.
Hefei University of Technology proposed a swing rod axial buckling chuck (Swing Rod Axial Buckling Chuck; Patent Application No.: CN 201210212982.1). The program is designed with a power chuck body and a clamping chuck body, wherein three chutes are uniformly distributed along a radial direction and are embedded with bottom claws and push claws, and a swing rod assembly is provided on the upper side. With such structure, the problem that a traditional chuck has difficulty in clamping a workpiece with a complicated structure is solved. Yet, this program still has a drawback that its use of axial clamping is not suitable for clamping thin-walled cylindrical workpieces.
BEIJING SEVENSTAR HUACHANG ELECTRONICS CO., LTD. proposed a disk clamping device (Disk Clamping Device, Patent Application No.: CN 201110365937.5). The program mainly includes a chuck main body, a cam, a stop block and at least three clamping members, wherein the stop block fixes the clamping member in the radial direction of the chuck main body when the cam rotates along with the chuck main body. Such structure is characterized in that the clamping position of the mechanical hand is not limited and clamping of a disk is realized without damaging the clamped object. Yet, the problem of the program lies in that it uses an outside chuck and the clamping member may cause deformation of the contour outline of the clamped object, which cannot be ignored for ultra-precision parts.
U.S. Pat. No. 4,840,387 proposed a clamping device in which the split nuts and chuck are mutually fitted and locked. Such structure is characterized in that it has high reliability and tightening of the chuck can be easily adjusted by hand, but the problem lies in that its structure is a little bit complex, so it is necessary to correspondingly enlarge the device in proportion when clamping large workpieces, resulting in increased friction during adjustment, which is not conducive to assembly and clamping.
Generally, the traditional three-jaw chuck and multi-jaw chuck clamping mechanisms may cause irreparable damages to the surface of the workpiece during assembly due to their own natural defects of applying uneven forces to the workpiece. In addition, with the constant emerge of more and more large and ultra-large annular workpieces, volume of the traditional three-jaw chuck and multi-jaw chuck clamping mechanisms should be enlarged as the outer diameter of the circular ring increases, which provides them less advantage in terms of economic cost and limits the designers in designing large annular workpieces at the same time.
Therefore, to design a clamping device which can overcome the drawbacks of the traditional chuck structure and also has the advantages of high stability, precise positioning, less damage to the workpiece surface is important for the manufacture of precision equipment.